PHP ActiveX Requires Chilkat v11.0.0+

RSA Encrypt/Decrypt Bytes

See more RSA Examples

Demonstrates how to RSA encrypt and decrypt byte data. PHP ActiveX

<?php

$success = 0;

//  The RSA public key is used for encryption, and the private key for decryption.

//  The public key's role is to make encryption accessible to anyone while ensuring that
//  only the private key holder can decrypt the messages.
//  The public key is designed to be widely distributed so anyone can use it to encrypt messages
//  intended for the owner of the private key.

//  Load our 2048-bit RSA public key.
$pubKey = new COM("Chilkat.PublicKey");
//  In all Chilkat methods expecting a path, you pass either absolute or relative paths.
$success = $pubKey->LoadFromFile('qa_data/rsaKeys/myTestRsaPublic.pem');
if ($success == 0) {
    print $pubKey->LastErrorText . "\n";
    exit;
}

$rsa = new COM("Chilkat.Rsa");

//  Tell RSA to use the public key.
$rsa->UsePublicKey($pubKey);

//  RSA encryption is for small amounts of data, on the order of 200 bytes or less.
//  The maximum number of bytes that can be RSA encrypted depends
//  on the RSA key size and padding scheme (OAEP padding vs PKCS#1 v1.5 padding).
//  For specific limits, see: RSA Encryption Maximum Number of Bytes

//  A typical use for RSA is to encrypt symmetric encryption keys, such as an AES key.
$prng = new COM("Chilkat.Prng");

$keyBytes = $prng->GenRandomBytes(32);

$encBytes = $rsa->EncryptBytes($keyBytes,0);

//  ------------------------------------------------------------------------------------------------------------------------
//  Let's decrypt, which requires the matching private key...

//  Load the matching 2048-bit RSA private key.
$privKey = new COM("Chilkat.PrivateKey");
$password = 'secret';
$success = $privKey->LoadAnyFormatFile('qa_data/rsaKeys/myTestRsaPrivate.pem',$password);
if ($success == 0) {
    print $privKey->LastErrorText . "\n";
    exit;
}

//  Tell the RSA object to use the private key.
$rsa->UsePrivateKey($privKey);

$decBytes = $rsa->DecryptBytes($encBytes,1);
if ($success == 0) {
    print $rsa->LastErrorText . "\n";
    exit;
}

print 'Success.' . "\n";

?>